sh: Add support for 4K stacks.

This enables support for 4K stacks on SH.

Currently this depends on DEBUG_KERNEL, but likely all boards
will switch to this as the default in the future.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/include/asm-sh/irq.h b/include/asm-sh/irq.h
index dd05e10..0e5f365 100644
--- a/include/asm-sh/irq.h
+++ b/include/asm-sh/irq.h
@@ -719,6 +719,15 @@
 #define irq_canonicalize(irq)	(irq)
 #define irq_demux(irq)		__irq_demux(sh_mv.mv_irq_demux(irq))
 
+#ifdef CONFIG_4KSTACKS
+extern void irq_ctx_init(int cpu);
+extern void irq_ctx_exit(int cpu);
+# define __ARCH_HAS_DO_SOFTIRQ
+#else
+# define irq_ctx_init(cpu) do { } while (0)
+# define irq_ctx_exit(cpu) do { } while (0)
+#endif
+
 #if defined(CONFIG_CPU_SUBTYPE_SH73180)
 #include <asm/irq-sh73180.h>
 #endif